Halloysite nanotubes filled with salicylic acid and sodium diclofenac: effects of vacuum pumping on loading and release properties

Abstract

In this work, we investigated the effects of the vacuum pumping on both the loading efficiencies and the release kinetics of halloysite nanotubes filled with drug molecules dissolved in ethanol. As model drugs, salicylic acid and sodium diclofenac were selected. For comparison, the loading of the drug molecules was conducted on platy kaolinite to explore the key role of the hollow tubular morphology on the filling mechanism of halloysite. The effects of the pressure conditions used in the loading protocol were interpreted and discussed on the basis of the thermodynamic results provided by Knudsen thermogravimetry, which demonstrated the ethanol confinement inside the halloysite cavity. Several techniques (TEM, FTIR spectroscopy, DLS and $$\zeta$$ ζ -potential experiments) were employed to characterize the drug filled nanoclays. Besides, release kinetics of the drugs were studied and interpreted according to the loading mechanism. This work represents a further step for the development of nanotubular carriers with tunable release feature based on the loading protocol and drug localization into the carrier. Graphic abstract The filling efficiency of halloysite nanotubes is enhanced by the reduction of the pressure conditions used in the loading protocol.

PEGylated green halloysite/spinel ferrite nanocomposites for pH sensitive delivery of dexamethasone: A potential pulmonary drug delivery treatment option for COVID-19

“…Further, the appearance of carbonyl functional moieties confirms the effective coating of PEG around Dex loaded ZnFe 2 O 4 /Hal. Therefore, such a charge distributions exhibits an electrostatic and van der Waals interactions and influence the drug adsorption and release behavior ( Lisuzzo et al, 2021 ). It is further reported that a drug Ibuprofen loaded inside the lumen part of Hal with strong affinity assist a prolonged release, while fast release occurs with weak hydrogen bonding of drugs residing on the surface of Hal ( Tan et al, 2014 ).…”

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